Expedition bag for long high-altitude ascents and polar challenges, cut wide enough to accommodate a full set of down clothing.

Typical Operating Temperature

Guideline minimum temperature. Sleeping Bag TOT: you should get a night’s sleep, under normal circumstances. Clothing TOT: you should feel warm enough, assuming low/moderate activity. Sleep System TOT: relates to full system. For more details, see our Technical Briefing.

-38°C / -36.4°F

Weight

For clothing, weight is for size: M. For sleeping bags, weight changes with selected length/width. N.B. there may be some variation in the weights of finished products.

†Please note: We make our stuff sacs big enough to allow fairly easy stuffing rather than reducing the bag to the tightest minimum.

*Please note: For all length and width options we change the amount of downfill to keep the warmth (TOT) the same.

‡Please note: The optional HS2 outer is a complete extra outer shell, with seams taped for weatherproofness. The extra layer of fabric adds considerably to the weight and bulk of the basic bag. It increases the weatherproof qualities of the bag in mountain or arctic situations, but it is not a substitute for a proper bivvy bag when sleeping out in the rain.

Description:

Ideal for long expeditions in extremely cold conditions, this Xero Down sleeping bag has been expressly designed to accommodate down clothing, even a full down suit.

The sophisticated baffle system is designed for excellent down control, while the short zip and down-filled gusset combination makes it completely fail-safe.

It is cut wide, with an inner measurement of 164cm around at the chest (enough to accommodate even down clothing inside) expanding to 182cm with the gusset open. A full-length zip version is also available for maximum ventilation.

950 down option

This option extends the range of this bag down to -42°C. Weight stays the same.

Technical info

Water-resistant Drishell outer fabric (weight: 54 gsm)

Ripstop nylon with an ultralight coating: achieves total windblock, along with high breathability and superior water resistance. Superbly efficient for a very light overall fabric weight.

Superlight MX fabric (weight: 32 gsm)

A mini-ripstop nylon with excellent tear strength, MX is the pick of the superfine 15 denier downproof materials. We have tested lighter fabrics, but most have had significant drawbacks, while our confidence in MX is based on several years of extensive use in both our ultralight and our high mountain gear.

Zips

The default zip on Xero bags is a short zip with a gusset. This is a fail-safe design. The short zip is backed by a down-filled gusset, so that when the zip is opened, the bag expands instead of opening right up. Not good for ventilation, but extra security in extreme situations in case of zip failure:

A full-length zip protected by double draft tubes is available as an option. Full zip bags ventilate well, so they can be used over a wider range of temperatures:

950 fillpower down

A newcomer to our range. European goose of rare quality. A high value alternative at the top levels of performance.
More on our down insulation.

900 Fillpower Down

European goose down of very high quality. A truly excellent down with large clusters, consistent quality and lively long-term performance. More on our down insulation.

Construction

PHD's trapezoid baffle system is used throughout. This is the best of the technical baffle systems, combining excellent down control with low baffle weight. In cross section the baffle system looks like this:

The design has a close-fitting down-filled mummy hood, and side V-channels which ensure all areas of the body are insulated. The baffles over the chest are vertically aligned, which stops any horizontal shifting of the down caused by arm movement during the night.

Proofed inner panels

Proofed fabric (Drishell or Ultrashell) panels are included inside the hood and foot areas of the bag to help keep the down dry. In very cold temperatures your breath can cause ice to form around the face opening, which may soak into the down as it melts. The panels at the foot end are to protect the down if you get into your bag with wet socks (or in extreme situations with your boots on).

Waterproof HS2 outer fabric (weight: 88 gsm)

HS2 is PHD's high-spec 2-layer ripstop for waterproof outers on our down. It is light enough to be the optional taped shell on our sleeping bags and tough enough for expedition use in our Omega clothing. HS2 is completely waterproof (when the seams are taped) and offers excellent breathability.